<?php
/* vim: set expandtab tabstop=4 shiftwidth=4: */
// +----------------------------------------------------------------------+
// | PHP Version 4														|
// +----------------------------------------------------------------------+
// | Copyright (c) 1997-2002 The PHP Group								|
// +----------------------------------------------------------------------+
// | This source file is subject to version 2.02 of the PHP license,	  |
// | that is bundled with this package in the file LICENSE, and is		|
// | available at through the world-wide-web at						   |
// | http://www.php.net/license/2_02.txt.								 |
// | If you did not receive a copy of the PHP license and are unable to   |
// | obtain it through the world-wide-web, please send a note to		  |
// | license@php.net so we can mail you a copy immediately.			   |
// +----------------------------------------------------------------------+
// | Author: Xavier Noguer <xnoguer@php.net>							  |
// | Based on OLE::Storage_Lite by Kawai, Takanori						|
// +----------------------------------------------------------------------+
//
// $Id: OLE.php,v 1.3 2006/02/19 10:31:20 stronk7 Exp $


/**
* Constants for OLE package
*/
define('OLE_PPS_TYPE_ROOT',		5);
define('OLE_PPS_TYPE_DIR',		 1);
define('OLE_PPS_TYPE_FILE',		2);
define('OLE_DATA_SIZE_SMALL', 0x1000);
define('OLE_LONG_INT_SIZE',		4);
define('OLE_PPS_SIZE',		  0x80);

require_once('PEAR.php');
require_once 'OLE/PPS.php';

/**
* OLE package base class.
*
* @author   Xavier Noguer <xnoguer@php.net>
* @category Structures
* @package  OLE
*/
class OLE extends PEAR
{
	/**
	* The file handle for reading an OLE container
	* @var resource
	*/
	var $_file_handle;

	/**
	* Array of PPS's found on the OLE container
	* @var array
	*/
	var $_list;

	/**
	* Creates a new OLE object
	* Remember to use ampersand when creating an OLE object ($my_ole =& new OLE();)
	* @access public
	*/
	function OLE()
	{
		$this->_list = array();
	}

	/**
	* Reads an OLE container from the contents of the file given.
	*
	* @acces public
	* @param string $file
	* @return mixed true on success, PEAR_Error on failure
	*/
	function read($file)
	{
		/* consider storing offsets as constants */
		$big_block_size_offset = 30;
		$iBdbCnt_offset		= 44;
		$bd_start_offset	   = 68;

		$fh = @fopen($file, "r");
		if ($fh == false) {
			return $this->raiseError("Can't open file $file");
		}
		$this->_file_handle = $fh;

		/* begin reading OLE attributes */
		fseek($fh, 0);
		$signature = fread($fh, 8);
		if ("\xD0\xCF\x11\xE0\xA1\xB1\x1A\xE1" != $signature) {
			return $this->raiseError("File doesn't seem to be an OLE container.");
		}
		fseek($fh, $big_block_size_offset);
		$packed_array = unpack("v", fread($fh, 2));
		$big_block_size   = pow(2, $packed_array['']);

		$packed_array = unpack("v", fread($fh, 2));
		$small_block_size = pow(2, $packed_array['']);
		$i1stBdL = ($big_block_size - 0x4C) / OLE_LONG_INT_SIZE;

		fseek($fh, $iBdbCnt_offset);
		$packed_array = unpack("V", fread($fh, 4));
		$iBdbCnt = $packed_array[''];

		$packed_array = unpack("V", fread($fh, 4));
		$pps_wk_start = $packed_array[''];

		fseek($fh, $bd_start_offset);
		$packed_array = unpack("V", fread($fh, 4));
		$bd_start = $packed_array[''];
		$packed_array = unpack("V", fread($fh, 4));
		$bd_count = $packed_array[''];
		$packed_array = unpack("V", fread($fh, 4));
		$iAll = $packed_array[''];  // this may be wrong
		/* create OLE_PPS objects from */
		$ret = $this->_readPpsWks($pps_wk_start, $big_block_size);
		if (PEAR::isError($ret)) {
			return $ret;
		}
		return true;
	}

	/**
	* Destructor (using PEAR)
	* Just closes the file handle on the OLE file.
	*
	* @access private
	*/
	function _OLE()
	{
		fclose($this->_file_handle);
	}

	/**
	* Gets information about all PPS's on the OLE container from the PPS WK's
	* creates an OLE_PPS object for each one.
	*
	* @access private
	* @param integer $pps_wk_start   Position inside the OLE file where PPS WK's start
	* @param integer $big_block_size Size of big blobks in the OLE file
	* @return mixed true on success, PEAR_Error on failure
	*/
	function _readPpsWks($pps_wk_start, $big_block_size)
	{
		$pointer = ($pps_wk_start + 1) * $big_block_size;
		while (1)
		{
			fseek($this->_file_handle, $pointer);
			$pps_wk = fread($this->_file_handle, OLE_PPS_SIZE);
			if (strlen($pps_wk) != OLE_PPS_SIZE) {
				break; // Excel likes to add a trailing byte sometimes 
				//return $this->raiseError("PPS at $pointer seems too short: ".strlen($pps_wk));
			}
			$name_length = unpack("c", substr($pps_wk, 64, 2)); // FIXME (2 bytes??)
			$name_length = $name_length[''] - 2;
			$name = substr($pps_wk, 0, $name_length);
			$type = unpack("c", substr($pps_wk, 66, 1));
			if (($type[''] != OLE_PPS_TYPE_ROOT) and
				($type[''] != OLE_PPS_TYPE_DIR) and
				($type[''] != OLE_PPS_TYPE_FILE))
			{
				return $this->raiseError("PPS at $pointer has unknown type: {$type['']}");
			}
			$prev = unpack("V", substr($pps_wk, 68, 4));
			$next = unpack("V", substr($pps_wk, 72, 4));
			$dir  = unpack("V", substr($pps_wk, 76, 4));
			// there is no magic number, it can take different values.
			//$magic = unpack("V", strrev(substr($pps_wk, 92, 4)));
			$time_1st = substr($pps_wk, 100, 8);
			$time_2nd = substr($pps_wk, 108, 8);
			$start_block = unpack("V", substr($pps_wk, 116, 4));
			$size = unpack("V", substr($pps_wk, 120, 4));
			// _data member will point to position in file!!
			// OLE_PPS object is created with an empty children array!!
			$this->_list[] = new OLE_PPS(null, '', $type[''], $prev[''], $next[''],
										 $dir[''], OLE::OLE2LocalDate($time_1st),
										 OLE::OLE2LocalDate($time_2nd),
										 ($start_block[''] + 1) * $big_block_size, array());
			// give it a size
			$this->_list[count($this->_list) - 1]->Size = $size[''];
			// check if the PPS tree (starting from root) is complete
			if ($this->_ppsTreeComplete(0)) {
				break;
			}
			$pointer += OLE_PPS_SIZE;
		}
	}
 
	/**
	* It checks whether the PPS tree is complete (all PPS's read)
	* starting with the given PPS (not necessarily root)
	*
	* @access private
	* @param integer $index The index of the PPS from which we are checking
	* @return boolean Whether the PPS tree for the given PPS is complete
	*/
	function _ppsTreeComplete($index)
	{
		if ($this->_list[$index]->NextPps != -1) {
			if (!isset($this->_list[$this->_list[$index]->NextPps])) {
				return false;
			}
			else {
				return $this->_ppsTreeComplete($this->_list[$index]->NextPps);
			}
		}
		if ($this->_list[$index]->DirPps != -1) {
			if (!isset($this->_list[$this->_list[$index]->DirPps])) {
				return false;
			}
			else {
				return $this->_ppsTreeComplete($this->_list[$index]->DirPps);
			}
		}
		return true;
	}

	/** 
	* Checks whether a PPS is a File PPS or not.
	* If there is no PPS for the index given, it will return false.
	*
	* @access public
	* @param integer $index The index for the PPS
	* @return bool true if it's a File PPS, false otherwise
	*/
	function isFile($index)
	{
		if (isset($this->_list[$index])) {
			return ($this->_list[$index]->Type == OLE_PPS_TYPE_FILE);
		}
		return false;
	}

	/** 
	* Checks whether a PPS is a Root PPS or not.
	* If there is no PPS for the index given, it will return false.
	*
	* @access public
	* @param integer $index The index for the PPS.
	* @return bool true if it's a Root PPS, false otherwise
	*/
	function isRoot($index)
	{
		if (isset($this->_list[$index])) {
			return ($this->_list[$index]->Type == OLE_PPS_TYPE_ROOT);
		}
		return false;
	}

	/** 
	* Gives the total number of PPS's found in the OLE container.
	*
	* @access public
	* @return integer The total number of PPS's found in the OLE container
	*/
	function ppsTotal()
	{
		return count($this->_list);
	}

	/**
	* Gets data from a PPS
	* If there is no PPS for the index given, it will return an empty string.
	*
	* @access public
	* @param integer $index	The index for the PPS
	* @param integer $position The position from which to start reading
	*						  (relative to the PPS)
	* @param integer $length   The amount of bytes to read (at most)
	* @return string The binary string containing the data requested
	*/
	function getData($index, $position, $length)
	{
		// if position is not valid return empty string
		if (!isset($this->_list[$index]) or ($position >= $this->_list[$index]->Size) or ($position < 0)) {
			return '';
		}
		// Beware!!! _data member is actually a position
		fseek($this->_file_handle, $this->_list[$index]->_data + $position);
		return fread($this->_file_handle, $length);
	}
	
	/**
	* Gets the data length from a PPS
	* If there is no PPS for the index given, it will return 0.
	*
	* @access public
	* @param integer $index	The index for the PPS
	* @return integer The amount of bytes in data the PPS has
	*/
	function getDataLength($index)
	{
		if (isset($this->_list[$index])) {
			return $this->_list[$index]->Size;
		}
		return 0;
	}

	/**
	* Utility function to transform ASCII text to Unicode
	*
	* @access public
	* @static
	* @param string $ascii The ASCII string to transform
	* @return string The string in Unicode
	*/
	function Asc2Ucs($ascii)
	{
		$rawname = '';
		for ($i = 0; $i < strlen($ascii); $i++) {
			$rawname .= $ascii{$i}."\x00";
		}
		return $rawname;
	}

	/**
	* Utility function
	* Returns a string for the OLE container with the date given
	*
	* @access public
	* @static
	* @param integer $date A timestamp 
	* @return string The string for the OLE container
	*/
	function LocalDate2OLE($date = null)
	{
		if (!isset($date)) {
			return "\x00\x00\x00\x00\x00\x00\x00\x00";
		}

		// factor used for separating numbers into 4 bytes parts
		$factor = pow(2,32);

		// days from 1-1-1601 until the beggining of UNIX era
		$days = 134774;
		// calculate seconds
		$big_date = $days*24*3600 + gmmktime(date("H",$date),date("i",$date),date("s",$date),
											 date("m",$date),date("d",$date),date("Y",$date));
		// multiply just to make MS happy
		$big_date *= 10000000;

		$high_part = floor($big_date/$factor);
		// lower 4 bytes
		$low_part = floor((($big_date/$factor) - $high_part)*$factor);

		// Make HEX string
		$res = '';

		for ($i=0; $i<4; $i++)
		{
			$hex = $low_part % 0x100;
			$res .= pack('c', $hex);
			$low_part /= 0x100;
		}
		for ($i=0; $i<4; $i++)
		{
			$hex = $high_part % 0x100;
			$res .= pack('c', $hex);
			$high_part /= 0x100;
		}
		return $res;
	}

	/**
	* Returns a timestamp from an OLE container's date
	*
	* @access public
	* @static
	* @param integer $string A binary string with the encoded date
	* @return string The timestamp corresponding to the string
	*/
	function OLE2LocalDate($string)
	{
		if (strlen($string) != 8) {
			return new PEAR_Error("Expecting 8 byte string");
		}

		// factor used for separating numbers into 4 bytes parts
		$factor = pow(2,32);
		$high_part = 0;
		for ($i=0; $i<4; $i++)
		{
			$al = unpack('C', $string{(7 - $i)});
			$high_part += $al[''];
			if ($i < 3) {
				$high_part *= 0x100;
			}
		}
		$low_part = 0;
		for ($i=4; $i<8; $i++)
		{
			$al = unpack('C', $string{(7 - $i)});
			$low_part += $al[''];
			if ($i < 7) {
				$low_part *= 0x100;
			}
		}
		$big_date = ($high_part*$factor) + $low_part;
		// translate to seconds
		$big_date /= 10000000;
		
		// days from 1-1-1601 until the beggining of UNIX era
		$days = 134774;
		
		// translate to seconds from beggining of UNIX era
		$big_date -= $days*24*3600;
		return floor($big_date);
	}
}
?>
